7,984 research outputs found

    Std fimbriae-fucose interaction increases Salmonella-induced intestinal inflammation and prolongs colonization

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    Author summary The intestinal epithelium is a crucial biological interface, interacting with both commensal and pathogenic microorganisms. It’s lined with heavily glycosylated proteins and glycolipids which can act as both attachment sites and energy sources for intestinal bacteria. Fut2, the enzyme governing epithelial α1,2-fucosylation, has been implicated in the interaction between microbes and intestinal epithelial cells. Salmonella is one of the most important bacterial gastrointestinal pathogens affecting millions of people worldwide. Salmonella possesses fimbrial and non-fimbrial adhesins which can be used to adhere to host cells. Here we show that Salmonella expresses Std fimbriae in the gastrointestinal tract in vivo and exploit Std fimbriae to bind fucosylated structures in the mucus and on the intestinal epithelium. Furthermore, we demonstrate that the Std fimbriae-fucose interaction is necessary for bacterial colonization of the intestine and for triggering intestinal inflammation. These data lend new insights into bacterial adhesion-epithelial interactions which are essential for bacterial pathogenesis and key factors in determining tissue tropism and host susceptibility to infectious disease

    Medical student self-efficacy, knowledge and communication in adolescent medicine

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    Objectives To evaluate student self-efficacy, knowledge and communication with teen issues and learning activities. Methods Data were collected during the 8-week pediatric rotation for third–year medical students at a local children’s hospital. Students completed a self-efficacy instrument at the beginning and end of the rotation; knowledge and communication skills were evaluated during standardized patient cases as part of the objective structured clinical examination. Self-efficacy, knowledge and communication frequencies were described with descriptive statistics; differences between groups were also evaluated utilizing two-sample t-tests. Results Self-efficacy levels of both groups increased by the end of the pediatric rotation, but students in the two-lecture group displayed significantly higher self-efficacy in confidentiality with adolescents (t(35)=-2.543, p=0.02); interviewing adolescents, assessing risk, sexually transmitted infection risk and prevention counseling, contraception counseling were higher with marginal significance. No significant differences were found between groups for communication; assessing sexually transmitted infection risk was marginally significant for knowledge application during the clinical exam. Conclusions Medical student self-efficacy appears to change over time with effects from different learning methods; this higher self-efficacy may increase future comfort and willingness to work with this high-risk, high-needs group throughout a medical career

    Feasibility of Functional Neuroimaging to Understand Adolescent Women’s Sexual Decision Making

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    Purpose For young women, new sexual experiences normatively increase after puberty and coincide with extensive changes to brain regions governing self-regulation of risk behavior. These neurodevelopmental changes could leave some young women vulnerable for negative sexual outcomes, including sexually transmitted infection and unintended pregnancy. We evaluated the feasibility of using functional neuroimaging to understand the sexual decision making of adolescent women. Methods Adolescent women (N = 14; 14–15 years) completed enrollment interviews, a neuroimaging task gauging neural activation to appetitive stimuli, and 30 days of prospective diaries following the scan characterizing daily affect and sexual behaviors. Descriptive and inferential statistics assessed the association between imaging and behavioral data. Results Young women were highly compliant with neuroimaging and diary protocol. Neural activity in a cognitive-affective network, including prefrontal and anterior cingulate regions, was significantly greater during low-risk decisions. Compared with other decisions, high-risk sexual decisions elicited greater activity in the anterior cingulate, and low-risk sexual decision elicited greater activity in regions of the visual cortex. Young women's sexual decision ratings were linked to their sexual history characteristics and daily self-reports of sexual emotions and behaviors. Conclusions It is feasible to recruit and retain a cohort of female participants to perform a functional magnetic resonance imaging task focused on making decisions about sex, on the basis of varying levels of hypothetical sexual risk, and to complete longitudinal prospective diaries following this task. Preliminary evidence suggests that risk level differentially impacts brain activity related to sexual decision making in these women, which may be related to past and future sexual behaviors

    A novel patch micro electrode array for sensing ionic membrane currents

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    Ionic membrane currents play an important role during regeneration of nerve cells, embryonic development and wound healing processes. Measuring the intracellular ion currents across the cell membrane is important in understanding the cellular functions related to the ion activities. A novel patch micro electrode array (p-MEA) for measuring the ionic membrane currents without poisoning the cells due to emitting metal ions is described in this paper. Results on biocompatibility of the device are presented. We discuss the fabrication and working principle of p-MEA

    Parent-Child Sexual Communication Among Middle School Youth

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    Middle school youth (N=1472) in Central Indiana completed a survey about parent-adolescent sexual communi-cation. Being older, female, mixed race, ever had sex, ever arrested, and higher HIV knowledge were associatedwith more frequent sexual communication

    Extreme event ecology needs proactive funding

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    Commentary: Extreme events such as wildfires, hurricanes, and floods have increased in frequency and intensity. It is no longer a question of if, but rather when and where these events will occur (Stott 2016), with adverse impacts on essential ecosystemservices including clean water, harvestable materials, and carbon sequestration. In some cases, extreme events such as wildfires may have positive impacts on populations and ecosystems. Managing these impacts requires understanding how environmental context as well as ecosystem and disturbance characteristics drive system responses (Hogan et al. 2020). However, funding for ecological extreme events research, such as through the US National Science Foundation’s (NSF’s) RAPID program, is typically reactive. Pre-event data, a RAPID prerequisite, aretypically lacking or only sporadically available, and case studies of extreme events often arise from chance disturbances at existing long-term research sites. This reactive stochastic approach has seeded the literature with unplanned case studies describing individual events. While useful for meta-analyses (eg Patrick et al. 2022), such studies provide limited spatiotemporal inference and predictive capacity. Prioritizing the study of extreme events and empirically testing fundamental concepts in disturbance ecology is paramount (Aoki et al. 2022). (...

    Only Yes Means Yes: Sexual Coercion in Rural Adolescent Relationships

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    Purpose Sexual consent is important to healthy relationships; however, sexual coercion is common. We examine modifiable risk and protective factors for sexual coercion among high school students in a rural community. Methods We surveyed 10th graders (N = 442) in a rural, Midwestern, low-to-middle income county before receiving an evidence-based sex education program. Sexual coercion was a single item, “has anyone you were dating or going out with forced you to do sexual things that you did not want to do?” We examined associations between sexual coercion and demographics, risk behaviors, sexual self-efficacy, controlling relationship behaviors, parent communication, and adverse childhood experiences. Results Approximately 22% of females and 8% of males reported experiencing sexual coercion at least once in their lifetime. Gender differences emerged in associated risk and protective factors, including sexual sex efficacy, controlling relationship behaviors, parent–adolescent communication about sex, and adverse childhood experiences. Conclusions Sexual coercion is common among adolescents in rural communities. Prevention interventions should target modifiable risk and protective factors

    Hydrodynamic object recognition using pressure sensing

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    Hydrodynamic sensing is instrumental to fish and some amphibians. It also represents, for underwater vehicles, an alternative way of sensing the fluid environment when visual and acoustic sensing are limited. To assess the effectiveness of hydrodynamic sensing and gain insight into its capabilities and limitations, we investigated the forward and inverse problem of detection and identification, using the hydrodynamic pressure in the neighbourhood, of a stationary obstacle described using a general shape representation. Based on conformal mapping and a general normalization procedure, our obstacle representation accounts for all specific features of progressive perceptual hydrodynamic imaging reported experimentally. Size, location and shape are encoded separately. The shape representation rests upon an asymptotic series which embodies the progressive character of hydrodynamic imaging through pressure sensing. A dynamic filtering method is used to invert noisy nonlinear pressure signals for the shape parameters. The results highlight the dependence of the sensitivity of hydrodynamic sensing not only on the relative distance to the disturbance but also its bearing

    A general pattern of trade-offs between ecosystem resistance and resilience to tropical cyclones

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    Tropical cyclones drive coastal ecosystem dynamics, and their frequency, intensity, and spatial distribution are pre-dicted to shift with climate change. Patterns of resistance and resilience were synthesized for 4138 ecosystem time series from n = 26 storms occurring between 1985 and 2018 in the Northern Hemisphere to predict how coastal ecosystems will respond to future disturbance regimes. Data were grouped by ecosystems (fresh water, salt water, terrestrial, and wetland) and response categories (biogeochemistry, hydrography, mobile biota, sedentary fauna, and vascular plants). We observed a repeated pattern of trade-offs between resistance and resilience across analyses. These patterns are likely the outcomes of evolutionary adaptation, they conform to disturbance theories, and they indicate that consistent rules may govern ecosystem susceptibility to tropical cyclones
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